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#include #include #include void *producter_f(void *arg); void *consumer_f(void *arg); int buffer_has_item = 0; /*設置緩存數量*/ pthread_mutex_t mutex; /*設置互斥*/ int running = 1; int main (void) { pthread_t consumer_t; /*線程參數*/ pthread_t producter_t; /*不知道這句為什么不給我變藍色，初始化互斥*/ pthread_mutex_init(&mutex, NULL); /*創建線程*/ pthread_create(&producter_t, NULL, (void *)producter_f, NULL); pthread_create(&consumer_t, NULL, (void *)consumer_f, NULL); usleep(1); running = 0; /*等待線程退出，一個線程不能夠被多個線程等待*/ pthread_join(consumer_t, NULL); pthread_join(producter_t, NULL); /*銷毀互斥*/ pthread_mutex_destroy(&mutex); return 0; } void *producter_f(void *arg) { while (running) { pthread_mutex_lock(&mutex); /*加鎖，進入互斥區*/ buffer_has_item++; printf("product ,num:%d\n", buffer_has_item); pthread_mutex_unlock(&mutex); /*解鎖，離開互斥區*/ } } void *consumer_f(void *arg) { while (running) { pthread_mutex_lock(&mutex); buffer_has_item--; printf("consumer,num:%d\n",buffer_has_item); pthread_mutex_unlock(&mutex); } } /* *生產者消費者問題的信號量控制，可以與上述程序進行對比，出處--同上 */ #include #include #include void *producter_f(void *arg); void *consumer_f(void *arg); sem_t sem; int running = 1; int main (void) { pthread_t consumer_t; pthread_t producter_t; sem_init(&sem, 0, 16); /*信號量初始化*/ pthread_create(&producter_t, NULL, (void*)producter_f, NULL); pthread_create(&consumer_t, NULL, (void *)consumer_f, NULL); sleep(1); running = 0; pthread_join(consumer_t, NULL); pthread_join(producter_t, NULL); sem_destroy(&sem); /*銷毀信號量*/ return 0; } void *producter_f(void *arg) { int semval = 0; /*信號量的初始值*/ while (running) { usleep(1); sem_post(&sem); /*信號量+1*/ sem_getvalue(&sem, &semval);/*得到信號量的值*/ printf("pro,num:%d\n",semval); } } void *consumer_f(void *arg) { int semval = 0; while (running) { usleep(1); sem_wait(&sem); /*信號量-1*/ sem_getvalue(&sem, &semval); printf("con num:%d\n",semval); } } /* *條件變量來控制線程的同步，根據百度百科代碼改編而成，不肯定沒有錯誤 */ #include #include #include void decrement_count(void); void increment_count(void); /**/ pthread_mutex_t count_lock; /**/ pthread_cond_t count_nonzero; unsigned count; int main(void) { pthread_t decrement_t; pthread_t increment_t; /*初始化互斥*/ pthread_mutex_init(&count_lock, NULL); pthread_create(&decrement_t, NULL, (void*)&decrement_count, NULL); pthread_create(&increment_t, NULL, (void*)&decrement_count, NULL ); usleep(1); pthread_join(decrement_t, NULL); pthread_join(increment_t, NULL); pthread_mutex_destroy(&count_lock); return 0; } void decrement_count(void) { pthread_mutex_lock(&count_lock); while (count == 0) {/*使線程阻塞在一個條件變量上線程可以被函數pthread_cond_signal函數喚醒*/ pthread_cond_wait(&count_nonzero, &count_lock); } count = count - 1; pthread_mutex_unlock(&count_lock); } void increment_count(void) { pthread_mutex_lock(&count_lock); if (count == 0) {/*它用來釋放被阻塞在條件變量cond上的一個線程*/ pthread_cond_signal(&count_nonzero); } count = count + 1; pthread_mutex_unlock(&count_lock); } |
